Exercise: simple-linked-list

_templates/practice-exercise/testlib.red

@@ -68,8 +68,9 @@ context [
 			rejoin ["(ignored)"]
 		]
 
-		print [
+		print rejoin [
 			pad/with summary 40 #"."
+			"... "
 			result
 		]
 

_tools/generate-practice-exercise.red

@@ -93,8 +93,12 @@ write/lines/append  rejoin [exercise-path %/.docs/instructions.md]  instructions
 ;     ===========================
 print "       TEST SUITE ..."
 
-canonical-data: load-json read 
-	rejoin [github-problem-spec %/canonical-data.json]
+canonical-data: unless map? canonical-data: try [
+	load-json read 
+		rejoin [github-problem-spec %/canonical-data.json]
+] [
+	#( cases: [])
+]
 
 camel-to-kebab-case: function [
 	"Converts a string in camelCase to kebab-case"

config.json

@@ -178,7 +178,7 @@
         "prerequisites": [
           "basics"
         ],
-        "difficulty": 1
+        "difficulty": 2
       },
       {
         "slug": "resistor-color",
@@ -342,6 +342,21 @@
         ],
         "difficulty": 7
       },
+      {
+        "slug": "simple-linked-list",
+        "name": "Simple Linked List",
+        "status": "beta",
+        "uuid": "55399872-3758-4424-80a1-36b1f80ad7b2",
+        "practices": [
+          "blocks",
+          "loops",
+          "functions"
+        ],
+        "prerequisites": [
+          "loops"
+        ],
+        "difficulty": 7
+      },
       {
         "slug": "circular-buffer",
         "name": "Circular Buffer",

exercises/practice/simple-linked-list/.docs/instructions.md

@@ -0,0 +1,22 @@
+# Instructions
+
+Write a simple linked list implementation that uses Elements and a List.
+
+The linked list is a fundamental data structure in computer science,
+often used in the implementation of other data structures. They're
+pervasive in functional programming languages, such as Clojure, Erlang,
+or Haskell, but far less common in imperative languages such as Ruby or
+Python.
+
+The simplest kind of linked list is a singly linked list. Each element in the
+list contains data and a "next" field pointing to the next element in the list
+of elements.
+
+This variant of linked lists is often used to represent sequences or
+push-down stacks (also called a LIFO stack; Last In, First Out).
+
+As a first take, lets create a singly linked list to contain the range (1..10),
+and provide functions to reverse a linked list and convert to and from arrays.
+
+When implementing this in a language with built-in linked lists,
+implement your own abstract data type.

exercises/practice/simple-linked-list/.meta/config.json

@@ -0,0 +1,18 @@
+{
+	"blurb": "Write a simple linked list implementation that uses Elements and a List.",
+	"authors": [
+		"loziniak"
+	],
+	"contributors": [],
+	"files": {
+		"solution": [
+			"simple-linked-list.red"
+		],
+		"test": [
+			"simple-linked-list-test.red"
+		],
+		"example": [
+			".meta/example.red"
+		]
+	}
+}

exercises/practice/simple-linked-list/.meta/example.red

@@ -0,0 +1,56 @@
+Red [
+	description: {"Simple Linked List" exercise solution for exercism platform}
+	author: "loziniak"
+]
+
+
+to-array: function [
+	list [block! none!]
+	return: [vector!]
+] [
+	array: make vector! []
+	while [not none? list] [
+		append array list/1
+		list: list/2
+	]
+	array
+]
+
+from-array: function [
+	array [vector!]
+	return: [block! none!]
+] [
+	list: none
+	loop element: length? array [
+		list: reduce [array/(element) list]
+		element: element - 1
+	]
+	list
+]
+
+reverse-list: function [
+	list [block! none!]
+	return: [block! none!]
+] [
+	reversed: none
+	while [not none? list] [
+		reversed: reduce [list/1 reversed]
+		list: list/2
+	]	
+	reversed
+]
+
+
+from-array-and-back: function [
+	array [block!]
+	return: [block!]
+] [
+	to block!  to-array from-array  make vector! array
+]
+
+convert-reverse-convert-back: function [
+	array [block!]
+	return: [block!]
+] [
+	to block!  to-array reverse-list from-array  make vector! array
+]

exercises/practice/simple-linked-list/.meta/tests.toml

@@ -0,0 +1,13 @@
+[canonical-tests]
+
+# Convert an array to linked list, and then from linked list back to array
+"3b72d23a-4487-4632-8682-59684c875dd9" = true
+
+# Convert from array, reverse the list, and covert to array
+"70484949-cf28-4446-af05-e24f5ae8a265" = true
+
+# Convert empty array
+"02fb7cdd-ad7f-4d0b-88b7-a3e0ccfcb584" = true
+
+# Convert and reverse empty array
+"410ed9b3-d4cd-4969-bc5e-3909efed65d8" = true

exercises/practice/simple-linked-list/simple-linked-list-test.red

@@ -0,0 +1,54 @@
+Red [
+	description: {Tests for "Simple Linked List" Exercism exercise}
+	author: "loziniak"
+]
+
+#include %testlib.red
+
+test-init/limit %simple-linked-list.red 1
+; test-init/limit %.meta/example.red 1						; test example solution
+
+canonical-cases: [#(
+    description: {Convert an array to linked list, and then from linked list back to array}
+    input: #(
+        array: [3 6 1]
+    )
+    expected: [3 6 1]
+    function: "from-array-and-back"
+    uuid: "3b72d23a-4487-4632-8682-59684c875dd9"
+) #(
+    description: {Convert from array, reverse the list, and covert to array}
+    input: #(
+        array: [3 6 1]
+    )
+    expected: [1 6 3]
+    function: "convert-reverse-convert-back"
+    uuid: "70484949-cf28-4446-af05-e24f5ae8a265"
+) #(
+    description: {Convert empty array}
+    input: #(
+        array: []
+    )
+    expected: []
+    function: "from-array-and-back"
+    uuid: "02fb7cdd-ad7f-4d0b-88b7-a3e0ccfcb584"
+) #(
+    description: {Convert and reverse empty array}
+    input: #(
+        array: []
+    )
+    expected: []
+    function: "convert-reverse-convert-back"
+    uuid: "410ed9b3-d4cd-4969-bc5e-3909efed65d8"
+)]
+
+
+foreach c-case canonical-cases [
+	case-code: reduce [
+		'expect c-case/expected compose [
+			(to word! c-case/function) (values-of c-case/input)
+		] 
+	]
+
+	test c-case/description case-code
+]

exercises/practice/simple-linked-list/simple-linked-list.red

@@ -0,0 +1,17 @@
+Red [
+	description: {"Simple Linked List" exercise solution for exercism platform}
+	author: "" ; you can write your name here, in quotes
+]
+
+from-array-and-back: function [
+	array
+] [
+	cause-error 'user 'message ["You need to implement this function."]
+]
+
+convert-reverse-convert-back: function [
+	array
+] [
+	cause-error 'user 'message ["You need to implement this function."]
+]
+

exercises/practice/simple-linked-list/testlib.red

@@ -0,0 +1,80 @@
+Red [
+	description: {Unit testing library}
+	author: "loziniak"
+]
+
+
+context [
+	tested: 0
+	ignore-after: none
+	test-file: none
+
+	set 'test-init function [
+		file [file!]
+		/limit
+			ia [integer!]
+	] [
+		self/test-file: file
+		if limit [
+			self/ignore-after: ia
+		]
+	]
+
+	sandbox!: context [
+
+		expect: function [
+			expectation
+			code [block!]
+		] [
+			result: try [
+				catch code
+			]
+
+			if error? result [
+				either result/type = 'user [
+					result: make map! reduce ['error result/arg1]
+				] [
+					throw result
+				]
+			]
+
+			unless result = expectation [
+				throw rejoin [{FAILED. Expected: } expectation {, but got } result]
+			]
+
+			result
+		]
+	]
+
+	set 'test function [
+		summary [string!]
+		code [block!]
+		/extern
+			tested
+	] [
+		result: either any [
+			none? ignore-after
+			tested < ignore-after
+		] [
+			exercise: make sandbox! load test-file
+
+			code: bind code exercise
+
+			catch [
+				do code
+				"✓"
+			]
+		] [
+			rejoin ["(ignored)"]
+		]
+
+		print rejoin [
+			pad/with summary 40 #"."
+			"... "
+			result
+		]
+
+		tested: tested + 1
+	]
+
+]